Thanks for your help.
I have setup the email accounts on the config page, but I don't know how to access the different addresses when using Horde.
You access email accounts one by one using the full email address as the user's login name, and that email accounts password.
If you're logging in as the main cPanel user, and wanted to send out an email from one of the accounts, you'll need to create identities.
While in Horde, General Options > Personal Information > 'Select the identity you want to change' > Create a new one.
I couldn't see a ""more" button nor configure email client.
Be sure you're looking in the right place. There is no option to disable this that I'm aware of.
I have a problem with my ISP where sending email is being blocked,
Probably due to email being sent out on a port that your ISP blocks, like port 25. You should contact your Hosting Provider and ask him to change this.
I am trying to see the multiple accounts on Horde.
Having access to all email accounts as the main cPanel user, shouldn't really be used to send email, IMO.
Previously I was able to see multiple accounts in Outlook before the blocking problem started.
You're speaking of Webmail above, and then mentioning Outlook here. Two different beasts. As I said, if you have multiple email accounts, you are able to set them all up, in Outlook individually, and check each, or all as you wish.
If you're not configured properly, server side and in your email client (Outlook), you can get blocked. One place to check if your IP range is blocked, is here:
Blocklist Removal Center - The Spamhaus Project
If you find your IP is listed, read the details. For example:
Important: If you are using any normal email software (such as Outlook, Entourage, Thunderbird, Apple Mail, etc.) and you are being blocked by this Spamhaus PBL listing when you try to send email, the reason is simply that you need to turn on "SMTP Authentication" in your email program settings.
Hope you are keeping well,
All the Best,
I am, thank you.